Continuous processes and systems to reduce energy requirements of using zeolites for carbon capture under humid conditions

Abstract

The direct air capture (DAC) systems and methods efficiently and economically regenerate a desiccant bed without adding any thermal energy and without requiring any pressurization or depressurization of the desiccant reactors. The methods leverage water concentration differences in stream flows, the water concentration profile across a desiccant bed, and, optionally, exothermic water adsorption. These three elements, working in combination, are referred to as 'reverse dry flow regeneration' or a 'reverse dry air swing' regeneration process. Systems and methods for reverse flow regeneration include those for CODAC applications, but they are also applicable to point source carbon capture and other similar technologies that require initial gas dehydration before exposure to a hydrophilic material.